Question

Which of the following is an intensive property?
A.Surface tension and density
B.Surface tension and volume
C.Enthalpy mass and density
D.None of these

Answer 1

A property of a substance can be classified as either extensive or intensive property. The properties whose values are independent of the quantity of substance present in the system are known as intensive properties. The properties whose values are dependent on the quantity of substance present in the system are extensive properties.

Complete step by step solution:
Intensive properties are bulk properties and do not depend on the size of the substance or system. Intensive property is a physical property. They cannot be calculated and need to be measured experimentally. Some intensive properties are conductivity, pressure, pH, concentration, refractive index, etc.
The total value of an extensive property is equal to the sum of the values of parts of the system. They can be calculated. All colligative properties are also extensive properties. Some extensive properties are volume, internal energy, mass, length, etc.
We can convert extensive properties into intensive properties by specifying the unit amount of substance. In other words, the ratio of two extensive properties can give us an intensive property.
For instance, both mass and volume are extensive properties but mass per unit volume is density which is an intensive property. Similarly the force on a surface of liquid per unit length gives us surface tension which is an intensive property.
We know that both surface tension and density are intensive properties while enthalpy, mass and volume are all extensive properties.

Thus, the correct answer is A.

Note: Intensive and extensive are not exhaustive categories for the classification of properties. Some properties like resistance are neither intensive nor extensive. Resistance can be considered as a geometric property.